Barlow lenses extend the focal length of the telescope. They are often used to obtain two different levels of magnification with a single eyepiece. If you use a 2x Barlow lens with an eyepiece, the magnification doubles.
In an astronomical telescope, the image is laterally transposed and/or upside down. This is unimportant for astronomical observing, but for terrestrial observing it is important. Erecting lenses provide an upright and true-sided image.
Magnification factor and connection

Omegon
2x Barlow lense, achromatic, 1.25"
( 5 / 5 )
$ 39.90
ready for shipping in 24
h

Astro Professional
Barlowlinse für Newton-Reflektoren 2x, 1,25"
Sale price:
$ 10.90
$ 1.05
ready for shipping in 24
h

Omegon
1.25", 5X premium Barlow lens
$ 179.00
ready for shipping in 24
h

Omegon
Oberon Barlow lens 2.5x 2”
$ 159.00
ready for shipping in 24
h

Omegon
erecting lens 1,25"
( 4 / 5 )
$ 99.00
ready for shipping in 24
h

Omegon
3x Barlow lens, achromatic, 1.25"
$ 49.90
ready for shipping in 24
h

Omegon
erecting lens 1.5x, 1,25" for reflectors
$ 19.90
ready for shipping in 24
h

Omegon
2'', 2X premium Barlow lens
$ 199.00
ready for shipping in 24
h

Omegon
1.25", 2X premium Barlow lens
$ 149.00
ready for shipping in 24
h

Omegon
1.25", 3X premium Barlow lens
$ 159.00
ready for shipping in 24
h

Omegon
1.25'', 2X, 3 Element Barlow eyepiece
$ 99.00
ready for shipping in 24
h

Levenhuk
Barlow Lens ED 2x 2"
$ 158.00
ready for shipping in 24
h

Astro Professional
Barlowlinse für Refraktoren 2x, 1,25"
$ 10.90
ready for shipping in 24
h

Omegon
2x ED Barlow lense 2"
( 4 / 5 )
$ 99.00
ready for shipping in 24
h

ASToptics
BARLOW 2X (DOUBLING LENS) + T2 THREAD
$ 47.90
ready for shipping in 24
h

Vixen
2X Barlow lens with 31.7mm T2 thread
Our price:
RRP:
$ 63.00
$ 51.00
ready for shipping in 1-2
weeks

William Optics
2x Barlow lense for 1.25'' Binoviewers
$ 73.00
ready for shipping in 24
h

Dörr
Erecting lense 1''
$ 10.90
ready for shipping in 24
h

APM
Barlow Lens 6.25x 1.25"
$ 311.00
ready for shipping in 1-2
weeks

TeleVue
Barlow Lens Powermate 2x 2''
$ 590.00
ready for shipping in 24
h

TeleVue
2x 1.25" Barlow lens
$ 231.00
Product can be shipped as of 15.10.2023

TeleVue
Barlow Lens 5x Powermate 1,25"
$ 379.00
ready for shipping in 24
h

TeleVue
3x 1.25" Barlow lens
$ 231.00
ready for shipping in 24
h

TeleVue
Barlow Lens 2,5x Powermate 1,25"
$ 379.00
ready for shipping in 24
h

Baader
Barlow Lens 2.25x/1.3x Q 1.25"
( 4 / 5 )
$ 58.00
ready for shipping in 24
h

Coronado
Barlow Lens Cemax 2x 1,25"
Our price:
RRP:
$ 136.00
$ 126.00
ready for shipping in 24
h

Skywatcher
Deluxe 1.25", 2X Barlow eyepiece
$ 47.90
ready for shipping in 1-2
weeks

Bresser
Barlow Lens 2x 1.25"
Our price:
RRP:
$ 31.90
$ 25.90
ready for shipping in 24
h

Bresser
Barlow Lens 5x 1.25"
Our price:
RRP:
$ 53.00
$ 42.90
ready for shipping in 1-2
weeks

Bresser
3x 1.25" achromatic Barlow lens
$ 33.90
ready for shipping in 1-2
weeks

Celestron
T-adapter/Barlowlinse
$ 41.90
ready for shipping in 24
h

Baader
Hyperion 2.25X zoom Barlow lens
$ 141.00
ready for shipping in 1-2
weeks

TS Optics
3x Barlow lens, UB3S, 1.25''
$ 53.00
ready for shipping in 1-2
weeks

Celestron
Barlow Lens Omni 2x 1.25"
$ 63.00
ready for shipping in 24
h

TS Optics
Barlow Lens 2x 1.25"
$ 42.90
ready for shipping in 1-2
weeks

Celestron
X-Cel LX 1.25", 2X Barlow lens
$ 136.00
ready for shipping in 24
h